Drip chamber and method

ABSTRACT

A drip chamber having a flexibly resilient sleeve with memory and one-way inlet and outlet valves in each end of the sleeve, the valves respectively being in communication with a fluid source and an infusion tube. A control unit can be fingeractuated to determine a continuous drip at a constant rate from the inlet to the outlet valve. The method includes squeezing the sleeve to force fluid through the outlet valve into the infusion tube and thereafter allowing the sleeve to expand to draw fluid through the inlet tube into the sleeve.

United States Patet 51 May 23, 1972 2,784,733 3/1957 Martinez r. 137/399 FOREIGN PATENTS OR APPLICATIONS 1,235,482 5/1960 France 128/2141,118,247 3/1956 France ..l28/2l4 Primary Examiner-Dalton L. TruluckAtt0rney-Lynn G. Foster [57] ABSTRACT A drip chamber having a flexiblyresilient sleeve with memory and one-way inlet and outlet valves in eachend of the sleeve, the valves respectively being in communication with afluid source and an infusion tube. A control unit can be finger-actuatedto determine a continuous drip at a constant rate from the inlet to theoutlet valve. The method includes squeezing the sleeve to force fluidthrough the outlet valve into the infusion tube and thereafter allowingthe sleeve to expand to draw fluid through the inlet tube into thesleeve.

5 Claims, 9 Drawing Figures PATENTEUMAY 2 3 I972 INVENTOR.

LOUIS S. SANTO ERI BY I ATTORNEY DRIP CHAMBER AND METHOD BACKGROUND 1.Field of the Invention The invention relates to medical infusionapparatus and more particularly to a novel infusion fluid drip chamberand method.

2. The Prior Art It is well known to use drip chambers with infusionapparatus for accommodating visual observation of the rate at whichinfusion fluid is conducted into a patient. Conventional drip chambersare normally a generally cylindrical enlargement of an infusion tube andare in direct open communication simultaneously with a source ofinfusion fluid and with the end of the infusion tube used to penetratethe patients circulatory system. A constricted opening in the dripchamber causes the fluid to flow through the chamber in droplets. It hasbeen common practice to place a filter within the drip chamber to filterthe fluid droplets as they fall by gravity through the chamber.

The rate at which the fluid drips through the chamber is most frequentlydetermined by a pinch valve or the like located on a portion of theinfusion tube between the drip chamber and the fluid source.

Frequently, it is necessary or desirable to force infusion fluid such asblood into the patient at a rapid rate. This is particularly true wherephysical injury to the patient has caused loss of a dangerous volume ofblood. Until this present invention it has be necessary to use auxiliarypumping apparatus for delivering the fluid to the patient. For example,a hypodermic syringe can be used to rapidly inject the fluid. If thefluid is plasma, isotonic saline or the like, it becomes necessary toperform repeated venipunctures in order to rapidly inject the increasedfluid volume. The use of the hypodermic syringe is not a safe way ofrapidly infusing a large volume of whole blood because use of thehypodermic syringe causes hemolysis of the blood cells.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION The present invention,including apparatus and method, includes a flexible drip chamber havingan interiorly confined control unit and spaced unidirectional valves sothat infusion fluid is pumped when the chamber is finger-squeezed toforce fluid within the chamber into an attached infusion tube andthereafter expanded to draw fluid from the source into the chamber.

It is therefore a primary object of the present invention to provide animproved drip chamber and method.

It is another object of the present invention to provide a novel dripchamber and method which accommodate safe, forceful pumping of infusionfluid into a patient.

These and other objects and features of the present invention willbecome more fully apparent from the following description and appendedclaims taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic representation of infusion apparatus showninfusing fluid into a patients arm;

FIG. 2 is a perspective illustration of a presently preferred dripchamber embodiment of the invention;

FIGS. 3-6 are longitudinal cross sections respectively taken along lines3-3, 44, 5-5 and 6-6 of FIG. 2;

FIG. 7 is a cross sectional illustration of another presently preferredunidirectional valve embodiment of the invention;

FIG. 8 schematically illustrates the method of pumping fluid through thedrip chamber; and

FIG. 9 is still another unidirectional valve embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference is now madeto the several embodiments of the invention as illustrated in theFigures, like parts being designated with like numerals throughout.

THE STRUCTURE The infusion apparatus generally designated 16 conveysinfusion fluid from a source such as a bottle 18 through a conventionalinfusion tube 20 to an intravenous needle 22 which has previously beenproperly placed within the vein of a patients arm 24. Infusion fluid, asused herein, means isotonic saline, blood, plasma or any otherbiologically acceptable fluid used for medical treatment of patients.The bottle 18 is normally suspended in the air so that the fluidcontained thereby falls by force of gravity through the infusion tube20. Preferably, a drip chamber generally designated 26 is interposedbetween the infusion tube 20 and the bottle 18.

The drip chamber 26 is best illustrated in FIG. 2 and preferablycomprises a cylindrically shaped sleeve 28 which is formed oftransparent plastic material with memory, the sleeve 28 being elongatedand terminating in upper and lower ends 30 and 32 respectively. Anannular collar 34 is situated adjacent the end 30, collar 34 having fourradially projecting ribs 36. The sleeve 28 is heat sealed or otherwiseconnected to the collar 34 and ribs 36 in a fluid-tight relation.

The collar 34 circumscribes a portion of conduit 38. A portion of theconduit 38 projects out of the sleeve 28 through the collar 34 andcomprises a conically tapered tip 40 which is used to penetrate therubber seal (not shown) in the neck 42 (FIG. 1) of the bottle 18. Theexposed portion of conduit 38 has at least one elongated slot 44 whichallows fluid within the bottle 18 to enter the interior of conduit 38.Conduit 38 is integrally connected to and in fluid communication withthe interior of a control unit generally designated 46. The control unithas spaced annular discs 48 and 50 which urge the sleeve 28 outwardlyaway from the cylindrical central portion 52 of the unit 46. Centralportion 52 has opposed annular bosses 58 and a transverse bore 54opening to the exterior of the unit central of each boss 58.

A spool valve 56 is reciprocably situated within the bore 54, the spoolvalve 56 having a transverse through-bore (not shown) which isincrementally displaced into and out of alignment with the hollowinterior of conduit 38. Thus, the amount of fluid flowing from thebottle 18 through the conduit 38 to the interior of sleeve 28 may beselected by finger-squeezing the sleeve 28 between discs 48 and 50 toaxially displace the spool valve 56 until the desired drip rate isachieved, as will be subsequently more fully described.

As shown in FIGS. 3 and 4, the interior of central portion 52 is in opencommunication with the open end 39 of a terminal projection 60 disposedthrough an aperture 62 in the disc 50. The projection 60 has opposedinwardly tapered sides 64 which converge to a point 66. The projection60 is annularly reduced adjacent the tapered sides 64 so as to form arecess 68. A length of highly flexible rubber tubing 70 isconcentrically surmounted upon the recess 68 and preferably bonded tothe projection 60 in the position illustrated in FIGS. 3 and 4. The tube70 is substantially longer than the recess 68 so that the free end 72 isallowed to flex and bend.

The sloping sides 64 cause the flexible tube 70 to converge toward thefree end 72. The projection 60 and tube 70 cooperate to form aunidirectional flutter or flap valve which closes to the solid lineposition illustrated in FIG. 3 when the pressure exterior of the valveis greater than the pressure exerted by the fluid within projection 60and which opens to the dotted line position of FIG. 3 when the pressureexterior of the tube 70 drops below the pressure exerted by the fluidwithin the projection 60. When the tube 70 opens to the dotted lineposition, fluid is allowed to flow through the opening 74 in the freeend 72 of the tube.

Reference is now made to FIGS. 5 and 6 wherein a second unidirectionalvalve assembly generally designated 76 is illustrated. Valve assembly 76comprises a valve housing 78 which is cylindrical in configuration andwhich is adapted to telescopically receive the sleeve 28. An annularlyenlarged flange 80 integral with the housing 78 provides a seat for thesleeve 28 and, preferably, the sleeve 28 is bonded or otherwise sealedin fluid-tight relation to the housing 78. Housing 78 has a conicallytapered intermediate portion 82 which merges with an outwardlyprojecting boss 84. The tapered intermediate portion 82 defines anannular shoulder 86 upon which a filter cone 88 is disposed. The filtercone 88 is preferably formed of a mesh fabric material having acylindrical base 90 which telescopes tightly over the boss 84. Cone 88also has outwardly directed corners 92, the sides of the cone convergingto an apex 94. The configuration of the filter is particularlyadvantageous because maximum filtration can be accomplished with aminimum of exposed surface area of the filter material. The filterremoves fibrin and clot material which may exist in blood communicatedthrough the drip chamber 26 and also serves to insure that foreignparticles which may exist in other intravenous fluid material do notenter the infusion tube 20.

The housing 78 is interiorly hollow comprising cylindrical bore 96 inthe boss 84 which diverges outwardly at 98 to the diametrally enlargedcylindrical bore 100. The bore 100 is in open communication with ahollow conduit 102 interior of a downwardly projecting male coupling104. The infusion tube 20 is press-fit upon the male coupling 104 asillustrated in FIGS. 2 and 6.

A highly flexible synthetic tube 106, which may be substantially thesame as rubber tube 70 above described, is bonded to the periphery ofthe bore 96 so as to project into the bore 100. The tube 106 functionsas a flutter valve so that when fluid pressure within the bore 100 isgreater than the fluid pressure conducted through the bore 96, the valve106 will be collapsed, thereby preventing fluid from backing to theinterior of sleeve 28. Conversely, when the pressure within the sleeve28 is greater than pressure in the bore 100, fluid will flow freelythrough the opening 108 to the infusion tube 20.

Alternatively, the unidirectional valve embodiment illustrated in FIG. 7and generally designated 110 could be used. The valve 110 differs fromthe valve 76 in that the rubber tube 106 has been replaced with abuoyant spherical ball 112. The ball 112 has a diameter which is smallerthan the diameter of bore 100 and larger than the diameter 96. Thus, asfluid 114 is backed up into the bore 100, the ball 112 will seat at thejuncture of bore 96 and diverging bore 98 as shown in FIG. 7 therebypreventing the fluid 114 from flowing interior of the sleeve 28.

Another presently preferred unidirectional valve embodiment isillustrated in FIG. 9 and is generally designated 116. The valve 116differs from the valve embodiment 76 in that elongated male coupling 104is replaced with a shorter male coupling 118 upon which is telescopedthe infusion tube 20. If desired, the infusion tube may be bonded orotherwise permanently attached to the male coupling 118. The opening 120between the bore 100 and the exterior of male coupling 118 provides alocation for bonding the rubber tube 106 in a manner substantiallyidentical to the bonding of tube 106 in the bore 96 as above described.In the FIG. 9 embodiment, the tube 106 projects directly to the interiorof the infusion tube 20 and assumes an open or closed position dependingupon the pressure within the tube 20.

THE M ETHOD With continuing reference to FIGS. 1-6 and with particularreference to FIG. 8, the method of the present invention will now bedescribed. The described embodiments of the invention accommodate aregulated, continuous drip from the flutter valve 70 into the interiorof sleeve 28. The rate at which the fluid drips into the sleeve 28 willdepend upon the particular position of spool valve 56 within the bore54. Once the position has been set, it is protected from inadvertentdisplacement by the radially projecting discs 48 and 50.

When it is desired to change or otherwise adjust the setting of spoolvalve 56, the fingers may be positioned between the discs 48 and 50 andthe sleeve 28 thereafter squeezed between the fingers until the spoolvalve 56 can be manually displaced in either axial direction to adjustthe drip rate.

Frequently, it is desirable to accelerate the flow of fluid through theinfusion tube 20 into the patients arm 24 (FIG. 1). This is accomplishedby first partially filling the sleeve 28 with fluid 114 as shown in FIG.8. Thereafter, the thumb and forefinger 122 and 124, respectively, maybe placed on opposite sides of the sleeve 28 and the sleeve squeezed asshown in FIG. 8.

As the sleeve 28 is forcefully collapsed, the pressure interior ofsleeve 28 will be sufficiently great to force open flutter valve 106(FIGS. 5 and 6) or to force the ball 112 (FIG. 7) away from its seatedposition so that fluid will be forced into the tube 20. At the sametime, the increased pressure within the sleeve 28 will force the fluttervalve to the collapsed or closed position as shown in solid lines inFIG. 3, thereby preventing air within sleeve 128 from being conducted tothe interior of the bottle 18. Thus, since air is confined within thesleeve 28, substantial pressure can be developed within the sleeve 28 bycollapsing the sleeve only a relatively small amount.

After a volume of fluid has been forced into the infusion tube 20, thefingers may be removed from the sleeve 28 thereby allowing the sleeve,by force of the memory of the material forming sleeve 28, to return tothe configuration illustrated in FIG. 2. As sleeve 28 expands to theFIG. 2 configuration, the pressure interior of sleeve 28 will besubstantially reduced thereby allowing fluid to flow through conduit 38and valve 70 in a stream to the interior of sleeve 28. At the same time,the reduced pressure within the sleeve 28 will cause the flutter valve106 to collapse as shown in FIGS. 5 and 9 or, if the FIG. 7 embodimentis used, the ball 112 will seat. Thus, fluid within the valve 20 cannotbe drawn again into the interior of the sleeve 28.

When equilibrium pressure is reached within the sleeve 28, fluid willagain assume a continuous constant drip from the flutter valve 70 to theinterior of sleeve 28 and flutter valve 106 will allow fluid to passslowly into the tube 20. Alternatively, the ball 112 will be unseated atequilibrium pressure so that fluid will flow into the tube 20 asdescribed above. It is clear that repeatedly squeezing and releasing thesleeve 28 will cause the fluid to flow, pulsating under pressure throughthe infusion tube 20 into the patients arm 24. Thus, the presentinvention provides unitary structure and simplified method for pumpinginfusion fluid through an infusion tube under pressure and, when pumpingis no longer necessary, a uniform drip flow will be conducted throughthe infusion tube 20.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are, therefore, to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

l. A drip chamber for use with intravenous infusion apparatuscomprising:

an elongated tube of flexible material with memory in fluidcommunication with a source of infusion fluid through an upper endcoupling and in fluid communication with an infusion tube through alower end coupling,

a first one-way valve delivering fluid from the source to the interiorof the tube,

second one-way valve delivering fluid from the interior of said tube tothe infusion tube, and

flow rate regulating means located within said tube interposed betweensaid upper end coupling and said first oneway valve and formed withupper and lower radial flanges extending transversely of said tube and acentral portion of lesser diameter than said flanges extendinglongitudinally of said tube between said flanges formed with axial andtransverse intersecting bores and having a finger-positionable flowregulating member positioned within said transverse bore to regulate therate of flow of fluid to said first one-way valve.

2. The drip chamber of claim 1 wherein said tube is manually deformableintermediate said first and second oneway valves to permit manualpumping of fluid through said drip chamber.

3. A drip chamber for use with intravenous infusion apparatuscomprising:

an exterior wall of flexible material with memory formed into a closedsleeve, the sleeve being adapted to be in fluid communication with asource of intravenous fluid through an upper end coupling and adapted tobe in fluid communication with an infusion tube through a lower endcoupling, the upper and lower end couplings forming a fluid-tight sealin the respective sleeve ends;

a first one-way valve delivering fluid from the source to the interiorof the sleeve;

a second one-way valve delivering fluid from the interior of the sleeveto the infusion tube;

at least one of said one-way valves comprising a unidirectional flapvalve, the lumen of which is normally occluded and is selectivelyadditionally occluded by collapsing of the walls of the flap valve as aresult of pressure on the outside of the walls of the flap valve, thelumen being selectively dialated by pressure on the inside of the wallsof the flap valve, and flow rate regulating means located within saidsleeve interposed between said upper end coupling and said first one-wayvalve and formed with upper and lower radial flanges extendingtransversely of said tube and a central portion of lesser diameter thansaid flanges extending longitudinally of said tube between said flangesformed with axial and transverse intersecting bores and having a fingerpositionable flow regulating member positioned within said transversebore to regulate the rate of flow of fluid to said first one-way valve.

4. A chamber is defined in claim 3 wherein the second valve comprises aball check valve and the first valve comprises said flap valve.

5. A chamber as defined in claim 3 wherein each one-way valve comprisesone said flap valve.

1. A drip chamber for use with intravenous infusion apparatuscomprising: an elongated tube of flexible material with memory in fluidcommunication with a source of infusion fluid through an upper endcoupling and in fluid communication with an infusion tube through alower end coupling, a first one-way valve delivering fluid from thesource to the interior of the tube, second one-way valve deliveringfluid from the interior of said tube to the infusion tube, and flow rateregulating means located within said tube interposed between said upperend coupling and said first one-way valve and formed with upper andlower radial flanges extending transversely of said tube and a centralportion of lesser diameter than said flanges extending longitudinally ofsaid tube between said flanges formed with axial and transverseintersecting bores and having a finger-positionable flow regulatingmember positioned within said transverse bore to regulate the rate offlow of fluid to said first one-way valve.
 2. The drip chamber of claim1 wherein said tube is manually deformable intermediate said first andsecond one-way valves to permit manual pumping of fluid through saiddrip chamber.
 3. A drip chamber for use with intravenous infusionapparatus comprising: an exterior wall of flexible material with memoryformed into a closed sleeve, the sleeve being adapted to be in fluidcommunication with a source of intravenous fluid through an upper endcoupling and adapted to be in fluid communication with an infusion tubethrough a lower end coupling, the upper and lower end couplings forminga fluid-tight seal in the respective sleeve ends; a first one-way valvedelivering fluid from the source to the interior of the sleeve; a secondone-way valve delivering fluid from the interior of the sleeve to theinfusion tube; at least one of said one-way valves comprising aunidirectional flap valve, the lumen of which is normally occluded andis selectively additionally occluded by collapsing of the walls of theflap valve as a result of pressure on the outside of the walls of theflap valve, the lumen being selectively dialated by pressure on theinside of the walls of the flap valve, and flow rate regulating meanslocated within said sleeve interposed between said upper end couplingand said first one-way valve and formed with upper and lower radialflanges extending transversely of said tube and a central portion oflesser diameter than said flanges extending longitudinally of said tubebetween said flanges formed with axial and transverse intersecting boresand having a finger positionable flow regulating member positionedwithin said transverse bore to regulate the rate of flow of fluid tosaid first one-way valve.
 4. A chamber is defined in claim 3 wherein thesecond valve comprises a ball check valve and the first valve comprisessaid flap valve.
 5. A chamber as defined in claim 3 wherein each one-wayvalve comprises one said flap valve.